/*
 * Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 *
 */

package com.sun.imageio.plugins.png;

import java.io.IOException;
import java.util.Locale;
import java.util.Iterator;
import javax.imageio.ImageReader;
import javax.imageio.spi.ImageReaderSpi;
import javax.imageio.metadata.IIOMetadataFormat;
import javax.imageio.metadata.IIOMetadataFormatImpl;
import javax.imageio.stream.ImageInputStream;

public class PNGImageReaderSpi extends ImageReaderSpi {

    private static final String vendorName = "Oracle Corporation";

    private static final String version = "1.0";

    private static final String[] names = {"png", "PNG"};

    private static final String[] suffixes = {"png"};

    private static final String[] MIMETypes = {"image/png", "image/x-png"};

    private static final String readerClassName =
            "com.sun.imageio.plugins.png.PNGImageReader";

    private static final String[] writerSpiNames = {
            "com.sun.imageio.plugins.png.PNGImageWriterSpi"
    };

    public PNGImageReaderSpi() {
        super(vendorName,
                version,
                names,
                suffixes,
                MIMETypes,
                readerClassName,
                new Class[]{ImageInputStream.class},
                writerSpiNames,
                false,
                null, null,
                null, null,
                true,
                PNGMetadata.nativeMetadataFormatName,
                "com.sun.imageio.plugins.png.PNGMetadataFormat",
                null, null
        );
    }

    public String getDescription(Locale locale) {
        return "Standard PNG image reader";
    }

    public boolean canDecodeInput(Object input) throws IOException {
        if (!(input instanceof ImageInputStream)) {
            return false;
        }

        ImageInputStream stream = (ImageInputStream) input;
        byte[] b = new byte[8];
        stream.mark();
        stream.readFully(b);
        stream.reset();

        return (b[0] == (byte) 137 &&
                b[1] == (byte) 80 &&
                b[2] == (byte) 78 &&
                b[3] == (byte) 71 &&
                b[4] == (byte) 13 &&
                b[5] == (byte) 10 &&
                b[6] == (byte) 26 &&
                b[7] == (byte) 10);
    }

    public ImageReader createReaderInstance(Object extension) {
        return new PNGImageReader(this);
    }
}
